bjornsson



Dec. 22., 1925.

C. A. BJORNgSON INTERNAL COMBUSTION ENGINE Filed July 18 1924 5Sheeis-Sheet 1 I r1 TTOANE) Dec. 22 1925- 1,566,642

c. A. BJORNSSON INTERNAL COMBUSTION ENGINE Filed July 18. 1924 5Sheets-Sheet 2 $14 A TTORNE y Dec. 22 I 1925. 1,566,642

c. A. BJORNSSON INTERNAL COMBUSTION ENGINE Filed July 18 1924 3Sheets-Sheet 5 g/lfl. A BJORMSSON.

Z ,4 TTORNE y Patented Dec. 22,1925.

UNITED STATES;

A 1,566,642 PATENT OFFICE.

v CARL A. BJORNSSON, OF WELLSVILLE, NEW YORK, iASSIGNORIlO MGEWEN BROS.,OF WELLSVILLE, NEW YORK, A CORPORATION OF NEW YORK.

INTERNAL-COMBUSTION ENGINE.

Application filed July 18, 1924. Serial No. 726,663.

To all whom it may concern.

Be it known that I, CARL A. BJORNSSON,

a citizen of the United States, residing at \Vellsville, in the countyof Allegany and State of New York, have invented certain new and usefulImprovements in Internal- Combustion Engines, of which the following isa specification.

This invention relates to internal combustion engines of the oil orDiesel type and. more particularly, to a fuel injecting and controlapparatus for engines of this type.

In the usual type of four cycle, internal combustion, engines of thistype, the engine pistons make two complete reciprocations, and the crankshaft two revolutions, for each explosion and accordingly for eachinjection of fuel. The fuel injecting'pump must, therefore, be operatedat alternate revolutions of the crank shaft and this has usually beendone by driving the pump from the camshaft or other shaft rotating atone half the speed of the crank shaft. As the fuel pump must supply thefuel at a high pressure, the driving of the 'fuel pump from the camshaft has imposed a heavy stress on this shaft and its driving gears andhas necessitated the use of a more massive shaft and driving mechanismthan would otherwise be required.

- An object of my present invention is to provide a fuel injectingmechanism for four cycle internal combustion engines which may be drivendirectly from the crank shaft of the engine.

Another object of the invention is to provide a mechanism forcontrolling the quantity of fuel injected at each stroke of the pumpwhich will require a minimum of force or pressure from the overningmechanism and which will provi e a sensitive and responsive operation ofthe fuel control.

Further objects of the invention are to provide a means for driving afuel injecting pump from the crank shaft of an engine in which thedriving mechanism is moved out of driving position at alternaterotations of the shaft and in which the injection of fuel may be maderapidly in a very short period of time, and to provide a controllingfuel byass mechanism which will relieve or equalize the fluid-pressureon the valve immediately prior to its opening; a; v

\Vith these and other objects in view,

which will appear from the following description, the inventioncomprises the en-- gine and mechanism described and set forth 'in thefollowing specification and claims.

means embodying a preferred form of the invention, the section beingtaken on approximately the center line of the engine crank shaf Fig. 2is a vertical section of a portion ofthe engine and fuel injecting meanstaken on line 2-2 of Fig. 1, and,

Fig. 3 is an enlarged, sectional, view of the fuel injecting andregulating mechanism shown in Fig.2. a e In my presentinvention, thefuel injectmg pump or piston is driven directly from the engine crankshaft by a driving connection, which reciprocates with each revolutionof the crank shaft, and the feeding stroke of which is rendered inactivefor its respective cylinder at each alternate reciprocation,

preferably by being moved out of engage-v ment with the pump piston, sothat the pump is given a feeding thrust at alternate revolutions, oronce for each four cycles. A con- .stant quantity of fuel is drawn intothe fuel feeding pump on each suction stroke and the quantity offuelsupplied to the engine is controlled by by-passlng a portion of thisfuel through the inlet valve, which is for this purpose opened at asuitable portion of the feeding stroke,,the time of opening of thisvalve being controlled by a governor or regulator. The controllingmechanism comprises a floating lever, one end of which is raised andlowered by the piston driving means While the other end is fulcrumed ona control element which may be raised and lowered to control theposition of the lever and thus the point at which the fuel is bypassed.To reducethe force requiredto lift the inlet valve against the fluidpressure in the pump, a small by-passvalve is provided to 0 enimmediately prior to the opening of the inlet valve and to thus equalizethe pressures on opposite sides of this valve at the time of opening.

. Referring more particularly to the accompanying drawings, theinvention is illustrated as applied to an engine having a number 11 whenin alignment therewith. The stem lower portion of of fuel supply pumps10 and 11, two being shown by way of example, arranged; to supply acorresponding. number of engine cylinders, and mounted in a housing 12which also encloses the engine crank shaft 13. As the pumps 10. and 11are substantial duplicates, but one will be described, it beingunderstood that the description applies equally to both pumps.

The piston of each pump is driven from the crank shaft 13 by means of aneccentric 14 keyed, or otherwise rigidly secured, on the shaft andsurrounded by a suitable eccentric strap 15. The reciprocations of thestrap 15' are transmitted through a roller 16 mounted on a pin 17 in abracket 18 on the upper side of the strap 15 and adapted to strike andlift astem 19 depending from a piston 20 in a cylinder 21 of the pump 10or 19 and piston 20 are returned to their lowermost position by anysuitable means, as for example, by means of a spring 22 confined betweenthe under face of the pump'and a collar 23 mounted on the stem 19, andthe downward movement of the stem and piston is limited by means of ashoulder 24 on the thestem positioned to stop againsta guide collar 25on an inner wall of the crank casing 12.

Through the above described mechanlsm, if the roller 16 were kept inalignment with the piston stem 19 and the crank shaft axis,

i the eccentric 14 would give the piston a thrust at each revolution ofthe crank shaft and would thus feed fuel at every two cycles instead ofat each four cycles as desired. To render the fuel feed inactive at"alternate rotations of the crank shaft, the roller 16 is swung clear ofthc'piston stem at every other stroke by means of an eccentric 26 on ashaft 27 rotated at cam shaft speed, or at one half the speed of thecrank shaft, and connected to the roller 16 by means of a rod 28 havingat one end an eccentric strap 29 embracing the eccentric-26 and, at itsother end 30,

forked and secured to the pin 17. The angular position of the shaft 27is such, relative to the shaft 13, that during an upper stroke of theeccentric strap 15 and roller 16, the roller is held in alignment withthe piston stem 19 and crank shaft axis as indicated in full lines inFig. 2. Upon a complete revolution of the crank shaft and sub sequentupward stroke of the roller 16, the shaft 27 will havecompleted a halfrevolution, bringing the roller into the position indicated in brokenlines in Fig. 2 and thus into a osition in which the roller just clearsthe en of the piston stem. The pump piston is therefore driven upwardly,forcing a charge of fuel to the cylinder and returnlng and drawing in anew charge on one revolution of the crank shaft and remains'inactive onthe next succeeding revolution and upon the third revolution, againdriving the charge of fuel to the engine cylinder and drawing in a freshcharge.

It is to be noted that the forcing and suction movements of the pistonare much shorter and more rapid than would be the case if the drivingeccentric were rotating at cam shaft speed, thus enabling the injectionof the fuel to take place in-a shorter period of time and to be moreclosely and accurately timed. As the crank shaft must be of massiveconstruction to receive the thrusts of the engine pistons, it is welladapted for driving the fuel feed pumps and inasmuch as the guiding orcam shaft has merely to tilt the driving eccentric strap, it may be madeof light construction and imposes no considerable stress on its drivinggears.

The shaft 27 may be driven at cam shaft speed by any suitable orstandard means as indicated diagrammatically in Fig. 1, for example. Inthis case, the shaft 27 is driven from the crank shaft through a gear 31fixed on the crank shaft and meshing with an idler spur gear 32 mountedon a shaft 33 on which is, also mounted a gear 34 which in turn mesheswith and drives a spur gear '35 rigidly mounted on the shaft 27. Thediameters of the gears 31, 32, 34, and 35 are such as to reduce thespeed of the shaft 27 to one half that of the crank shaft as, forexample, by making the gear 32 of twice the diameter of the gear 31 andmaking the gears 34 and 35 of equal diameters.

Upon each downward stroke of the pump piston 20 a charge of fuel isdrawn from a source of supplythrough an inlet pipe 36 and a passage 37to a valve chamber 38 lifting an inlet check valve 39 therein, andthence passing through a passage 40 to the pump cylinder 21 to fill thecylinder with a charge of fuel.

As the piston 20 is again forced upwardly,

'the charge of fuel is forced backwardly combustion-chamberof the enginecylinder.

Upon each stroke of the pump piston, there fore, a fixed, constant,quantity of fuel is drawn into the pump cylinder and forced out, thisquantity being sufficient to drive the engine at maximum load.

1 When the engine is running at less than full load, a portion of thecharge of fuel is by-passed, on the delivery stroke, to the inletpassage 37 and permitted to return to the source of supply or to beagain drawn into the pump cylinder with the next charge. To this end, alever 43 for actuating the by-passing of the fuel is fulcrumed atone endon a vertically adjustable, horizontal, supporting rod 44 and pivotallyattached at its other end to the piston stem 19 in such a manner as tobe tilted upwardly. and downwardly on the rod'44 by the movement of thestem 19. A vertical valve actuating rod 46 is mounted on the lever 43between the fulcrum rod 44 and the piston stem 19 and extends upwardlyinto the valve chamber 38 to a suflicient distance to reach and lift thevalve 39 when the lever 43 is lifted to a sufficiently high position bythe fulcrum 44 and piston stem 19. The rod 46 and lever 43 are normallyheld downwardly on their supports by means of a spring 47 confinedbetween a flange 48 on the rod 46 and the under face of the valvechamber structure.

As the valve 39 is held downwardly on its seat by the full fluidpressure of the fuel in the outlet passages acting-on the entire surfaceof the valve, considerable force would be required to lift this valveagainst this fluid pressure. To diminish the force required to lift theinlet valve, the valve 39 is provided with a small, pressure release,

valve 49 seatingl on, and closing, a by-pass passage 50. in t e valve39, on which it is resiliently held by a spring 51 as well as by thefluid pressure in the valve chamber,

pressure on the lar er valve in time to en"- able it to be easily ifted.

For this purpose, the valve 39 is pro-- vided with a hollow, downwardlydepend- 'ing,;guide stem '52 having suitable guide vanes, and'the valve49 is provided with a downwardly depending stem 53, within the stem 52and projecting to a distance slight-' ly below the bottom of the stem 52when the valve 49 is seated on the valve 39. Accordingly, when the rod46 is brou ht upwardly,

against the stems 52 and 53, it ifts the stem 52 and valve 49 andimmediately thereafter reaches and lifts the stem 53 and permits thefuel to escape to the inlet pipe 36.

The point in the vertical movement of the piston 20 at which the rod 46opens the valve 39 is governed by the vertical position of thehorizontal fulcrum rod 44, which is so mounted eccentrically on arotatable journal 54 that, as the journal rotates the rod 44 is liftedor lowered. The position of the journal 54 and rod 44 may be controlledby a lever 55 connected .by a link 56 to a suitable control or governor.When the rod 44 is in its lowermost position, the lever 43 is fulcrumedso low that the rod 46 does not reach the stems 52 and 53 even when thepiston 20 reaches its upper limit of moveas at 59 to enable it to beturned by a wrench gland 66.

Iber to said piston.

ment and the full quantity of fuel is de livered to the engine cylinder,while, when the rod 44 is'in its uppermost position, the

inlet valve 39 is opened very early in the stroke of the .piston 20,thus delivering a minimum of fuel to the engine cylinders.

To enable the position of the governing lever 43 to be adjustedrelative'to its supporting and actuating elements, it is not mounteddirectly on the fulcrum rod 44 but is provided with averticallyadjustable stem 57 threaded in the end of the lever and havinga supportingsurface 58 on its lower end. The upper end of the stem 57 issquared and a lock nut 60 is provided to lock the stem 57 in position.With this arrangement, the control of the fuel feed may-be readilyadjusted. v

The'pump structure may be placed in any suitable, convenient position onthe engine.

It is preferably formed in a block mounted on the upper wall of'thecrank casing, which is provided with an opening 62 through whichthe-lower face of the block is open to the crank case and drivingmechanism. The pump cylinder is formed by a suitable hole or bore in thec linder block and a casing 63 held thereinv by means of a threadedretaining gland 64, which also serves as a supporting stop for the upperend of the spring 22. A sleeve 65 for the portion of the rod 46extending into the valve chamber 38 is similarly mounted and retained ini the pump block by means of a retaining As changes of constructioncouldbe made within the scope of my invention, it is desired that allmatter contained in the. above description-or shown in theaccompanyingdrawings shall be interpreted as'illustrative vandnot in alimiting sense.

' for transmitting a thrust from said crank shaft direct'to fuel to beforced to said cylinder, and means causing said pump to supply fuel tosaid 0 linder only on alternate revolutions of sai crankshaft. i 2.Any-internal combustion engine com-' 12 prisinga crank shaft, a fuelinjecting piston, a reciprocating member driven from said crank shaft.and means for transmitting alternate thrusts of said reciprocating mem-3. An internal combustion engine comprising a crank shaft,a fuelinjecting piston, an eccentric on said crank shaft, an eccentric strapon said eccentric, a reciprocating member driven from said strap, andmeans for swinging said reciprocating member out of alignment with saidpiston at alternate revolutions of said crank shaft.

4. An internal combustion engine which comprises a crank shaft, acylinder, a fuel pump for forcing fuel from a supply source to saidcylinder, said pump having means for transmitting a .thrust from saidcrank shaft direct to fuel to be forced to said cyl-' inder, and meansrendering said thrust transmitting means. inactive on alternaterevolutions of said crank shaft.

5. An internal combustion engine which comprises a crank shaft, a fuelinjecting means comprising a piston, means'driven from said crank shaftfor reciprocating said piston, a shaft, means for driving said shaft atone half the speed of said crank shaft, and means actuated from saidshaft to withdraw said reciprocating means from engagement with saidpiston ateach revolution of said shaft.

6. An internal combustion engine which comprises a crank shaft, a fuelinjecting means comprising a piston, a reciprocating member driven bysaid crank shaft and means comprising a piston, an eccentric on saidcrank shaft, an eccentric strap encircling said eccentric, a rollermounted on said eccentric strap, and means for moving said roller intoposition to. actuate said piston on alternate revolutions of said crankshaft.

8. An internalcombustion engine Which' comprises a crank shaft, a fuelinjecting means comprising a piston and a stem depending from saidpiston, an eccentric on said crank shaft,'an eccentric strap'encirclingsaid eccentric, a roller mounted on said eccentric strap, means formoving said roller into position to strike and move the piston stem onalternate revolutions of said crank shaft, and a spring for returningsaid piston and stem on the return movement of said roller.

9. An internal combustion engine which comprises a crank shaft, a fuelfeeding means comprising 'a piston driven by a direct thrust from saidcrank shaft and an inlet valve, means for rendering. said pistondrivingmeans lnactive on alternate rotations of said crankshaft, meansfor opening said inlet valve during the delivery stroke of said piston,a by-pa'ss valve for said inlet, means for opening said by-pass alveimmediately 'prior to the opening of said inlet valve, and means foradjusting the portion of said delivery stroke of said piston duringwhich said inlet valve is open.

In testimony whereof I affix my signature.

CARL A. BJORNSSON.

